The players can't believe they've made it to Week 19 - the week they'll learn who makes it to the Final Four. Hannah's amazed to find a huge shirt she wore during Week 1 - now both she and Olivia can fit in it together! The sisters can't believe they made it this far. More than anything she's ever wanted, Olivia wants to be in the finals together with Hannah. They resolve that neither of them will go home this week. After his close call last week, Jay promises to redeem himself. Alison stops by to announce that it's Final Exams Week. Each trainer has prepared a test, and each player will be graded on a scale from one to 100 for each test; and the winner will be announced after the last exam is complete. There will be spinning with Bob, motivating with Jillian, boxing with Cara, and a health and wellness quiz with Brett. The best cumulative grade wins $10,000!
Bob's test: the players have to teach him how to spin. Irene's terrified by this prospect. Even though she knows how to spin well, Bob grades her at 72 points for her loopy teaching technique. Olivia immediately takes control of her teaching session, and her grade reflects perfection - 100 points. Jay goes gonzo. His first move is to take the seat off the spin bike, which makes Bob nervous, since he's all about safety first. Jay fails this test, earning a mere 58 points. Despite Austin's nervousness, he hits safety points right off the bat and does a great job, winning 95 points. Hannah impresses Bob with her professionalism and earns herself 100 points.
Brett dresses up like his dad, a Princeton professor of neuroscience, to welcome the contestants to his classroom for the health and wellness quiz. Always a good student, Olivia does great, but Hannah only rates a C+ at 77 points - with punishment push-ups. Irene scores an 80, Jay gets 88, Olivia 83 and Austin 82. Meanwhile, Cara waits in the boxing ring to start her test. Olivia admits she's a bit spaztastic in the ring. It turns out Cara's test isn't a boxing test, it's a fighting test - so no smiling and no laughing during the face-off when Cara threatens to punch the contestants in the face. Admitting she's not the best boxer, Irene takes away 70 points. Fierce and serious, Olivia aces it with 100 points, hands down. Cara thinks Jay's really a fighter too, so he gets 95 points, and so does Austin. But Hannah... well, she gets docked for laughing, but still scores 92 points.
Since it's her last season, Jillian has decided to give the players a role-playing exam. She's going to play the contestant. Now who will be able to motivate her? Hannah immediately realizes what Jillian's up to - saying the kinds of things Hannah's been saying all along. Irene takes a different tact than Hannah and starts off by asking Jillian questions. Bob asks Jillian when she felt powerful, then draws her attention to her body cues, advising her to get her mind and body in sync. Austin steps up to the task with passion, and Olivia preaches self-care. Irene gets 85 points since she didn't quite emotionally connect, and Jay gets 90 points. Jillian's only complaint with Austin? She needs more how-to; but his passion is right up there, so he scores 85. Olivia didn't really challenge Jillian, so she scores 89. However, Hannah offered nine techniques, so she gets a 90.
Alison's waiting for everyone in the gym, which is filled with TV monitors and video games. The surprise? It's their last test, and they'll be playing The Biggest Loser Ultimate Workout on Kinect for Xbox 360, featuring the five of them! There are four exercises, and the contestants have to try to match their avatars' form as best they can. First place gets 100 points, second 90, and so on. This score will be added to their cumulative scores on the other tests. As it stands now, Olivia is in first place, and Irene is in last. Round 1 is Sumo Jump Squats, and they're giving Jay a run for his money. Round 2 is High Knee Jump Rope, a fast aerobic round, accompanied by Bob's tips. After two rounds, Hannah's in first place, and Olivia's in second.
Round 3 is Skating, and Hannah's in the zone, determined to work her avatar to the bone, until she begs for mercy. Then it's on to Round 4, Standing Mountain Climbers. Even though there's a part of Olivia that wants Hannah to win everything, she also can't help competing. But Hannah wins this one and the 100 points. Ali announces that the content seen on this episode will be available for free immediately afterwards on Xbox Live so people at home can see how they stack up against the players on the show. As for this week's challenge, Jay came in last, and it's between Hannah and Olivia for first. With three points difference between them, Olivia wins the $10,000 and an Xbox 360.
With the pressure to make it into the Final Four raging, the trainers gather the players for an intense workout. Jillian promises to beat the crap out of Jay, and boy, does she lay into him. She's still convinced he's had a certain apathy since his return to the ranch, and the closer he comes to breaking through, the more he shuts down. In fact, Jay does fall off the treadmill onto the floor. Jillian resolves that today she'll either switch him on or get him out of there. What's he doing this for? Jay admits he's doing it for his family, so Jillian points out that this will allow him to get through anything. Bob points out that the ranch experience has made Austin a man; now Austin's purpose is to be the best man he can be. As for Olivia, she feels like the champion of the world!
Cara finds Austin eating breakfast, the perfect opportunity to take about a fighter's diet. Since he's on a low-calorie diet, he's got to make every calorie count, and milk is a great way to do that. Later, Alison meets the contestants in a field to present this week's challenge - maybe their toughest yet. Each contestant has 100 sandbags, which they're going to use to climb to the top of an oversized set of stairs. They've got to stack 25 bags before proceeding to the next step. The first player to the top will hit a buzzer, raising a flag that will signal the win - and a one-pound advantage at the weigh-in. The three girls know how valuable this one pound could be for them. Austin takes an early lead, but Olivia and Irene are right on his heels. But at the end of the day, Austin makes his first challenge win in 32 minutes and one second.
The players leave the ranch for a Subway field trip with Brett, who wants to talk about the Sweet Onion Chicken Teriyaki Sandwich - and give them a pop quiz! The prize? A $500 Subway gift card... that goes to Hannah for guessing the number of calories in the sandwich. Later, Bob and Brett (the Killer Bs) meet Jay and Austin in the gym for their Last Chance Workout. As soon as Bob's done with the guys, Cara walks into the gym with the girls. Bob decides to stick around to help give the girls the Last Chance Workout of a lifetime.
Alison and the trainers are already in the gym waiting for the players to commence the weigh-in that will determine the Final Four. Of course, Alison has one last Finals Week test, offering Austin and Olivia a choice: Olivia can trade her challenge win of $10,000 for a one-pound advantage, and Austin can give up his one-pound advantage for $10,000. When asked for their opinions, Bob and Jillian debate - Bob thinks Olivia's worked hard enough to be safe, but Jillian knows that when the girls get small like a pencil, a pound can make all the difference in the world. Determined to make the Final Four, Austin keep his pound. Olivia keeps her $10,000, which she intends to use to take her husband on a trip, to kick off their new life together.
Hannah's up first - six pounds away from losing 100 - and loses four for 2.6%. Next week, she'll make her goal. Feeling more confident than ever, Irene heads for the scale to find out she lost five pounds for 3.29%. The scale shows Jay that he's finally back in form with a nine-pound loss. Olivia needs to have lost five pounds to stay above the yellow line - but if she does, she'll push Hannah below it. And she pulls it off! But with Austin yet to weigh in, she's still not safe, and Hannah's definitely below the yellow line. Jillian's furious that Olivia didn't use her $10,000 to buy the one-pound advantage. If she had, she'd have a guaranteed spot in the Final Four.
Austin stuns everyone by losing only one pound. It doesn't make sense, and he's in tears; but he tries to reassure himself. He can't be sad at having lost a total of 161 pounds - an entire man! - since he started the show. Now Hannah and Austin are below the yellow line, and Jay, Olivia and Irene will have to decide whom to vote off. Austin knows his chances of staying are nil... and he's right. But his journey really isn't over yet. He's in the game for the At-Home Winner and will be back for the finale.